Club Feet in Adult Horses

Some women love high heels. Walking in them might take some getting used to, but they provide the perfect look for big-city club-hopping or schmoozing at the latest gallery opening. They're not so great, though, for jogging or other sports. A horse with a club foot is kind of like a horse in high heels: The hoof angle becomes raised and the horse walks on his toe due to a shortening of the musculotendinous unit (the unit including the tendon that attaches under the foot and the muscles attaching above the knee). The condition most commonly affects only one front foot, but can involve any combination of feet. This is not exactly the ideal for good athleticism.

Usually, club feet are diagnosed and treated while the horse is still immature; this is one of the most common growth (orthopedic) problems in young horses and typically affects youngsters between birth and six months of age. Sometimes, though, the horse is an adult before he presents with the condition.

Getting a Late Start

There are several reasons why a veterinarian might be called out to deal with a mature horse with a club foot. "The majority are horses that had a club foot from birth to one year of age that hadn't been treated or treated properly," states Stephen O'Grady, DVM, MRCVS, who specializes in hoof and leg problems in his practice at Northern Virginia Equine.

In this case, a congenital or acquired club foot was ignored or poorly treated when the horse was a baby, and simply carried into adulthood, says Robert Sigafoos, chief of farrier services and director of the Applied Polymer Research Laboratory at the University of Pennsylvania's New Bolton Center. Sometimes, a mild congenital club foot is exacerbated later in life by long toes, infrequent shoeing, or an underlying problem.

Sigafoos adds that a club foot in the adult horse also can be acquired. "If this is an acquired condition, it is almost always secondary to an underlying pathology such as laminitis or a chronic lameness. It is important to realize that laminitis can be an insidious disease and, in some cases, absent of clinical signs such as lameness or changes at the coronary band. As a result, laminitis can be subclinical, but create long-term problems with the hooves."

Additionally, insufficient trimming, excessive trimming of the toe, or any response that results in pain in the hoof (generally the toe) can lead to a club foot. This is because with decreased weight bearing, the muscles above the tendons will contract due to myotactic reflex (the reflex in muscles that causes the musculotendinous unit to contract, thereby maintaining a uniform tension within the unit), O'Grady says.

The problem with trimming and shoeing the club-footed adult horse is that in many cases, the heels grow at a significantly faster rate than the toe. States Sigafoos, "This causes the hoof to gradually become more upright during the three to six weeks of the shoeing cycle (rather than just growing longer all around). This abnormal angle results in a misalignment of the coffin bone (the third phalanx, or P3) and, in some cases, detrimental changes to this bone. These changes can include 'remodeling' of the lower surface of the bone, fractures of the bone (particularly along the surface closest to the ground), and osteoporosis. Additionally, the abnormally upright foot and bone can cause painful bruising on the sole of the hoof in front of the frog. Because the heels tend to grow faster than the toe, if left unchecked the hoof will become increasingly upright and 'clubby.' "

Diagnosis

Identifying a club foot is pretty straightforward. Clinical signs provide the first clues: An increased hoof angle, heels not contacting the ground after trimming, and sometimes a prominent coronary band. Some horses show mild lameness. Radiographs can help confirm the diagnosis, clarify the severity, and show the length of toe and position of the coffin bone.

"Radiographs are a must for the practitioner and the farrier," O'Grady emphasizes. "A lateral X ray reveals the alignment of P3 within the hoof capsule, the sole depth present, and the severity of the coffin joint flexion, i.e. the amount the coffin joint is pulled forward by the shortened muscle-tendon unit. This will dictate your treatment." Radiographs are helpful trimming guides.

O'Grady recommends ranking severity by grades. "The severity of the club foot is dictated by how much shortening there is of the musculotendinous unit," he says.

Grade I--Hoof angle is 3-5° greater than the opposing foot, and there is increased fullness at the coronary band.

Grade II--Hoof angle is 5-8° degrees greater than the opposing foot, growth rings are wider at the heel than at the toe, and the heel doesn't touch the ground when trimmed to normal length.

Grade III--The anterior hoof wall is dished, growth rings at the heel are twice as wide as at the toe.

Grade IV--The anterior hoof wall is heavily dished with an angle of 80° or more, the coronary band is as high at the heel as at the toe, and the sole is below the ground surface of the hoof wall.

Treatment and Prognosis

Before treatment is initiated, it is important to differentiate between the acquired and the congenital club foot. Failure to treat an underlying causative condition of an acquired club foot can exacerbate the problem or result in a permanent debilitating lameness, says Sigafoos. "In the acquired condition, your veterinarian will attempt to identify the underlying cause and address the problem," he says.

Treatment varies according to severity. "In many cases, the best treatment is no treatment at all," Sigafoos continues. "Many animals will adapt to the club foot quite successfully. However, in more severe cases, horses are often treated quite successfully with surgical intervention along with corrective shoeing (particularly animals less than a year old). In some cases, adapted methods of corrective shoeing can bring about favorable results without surgery. But with very rare exception, the types of shoes used to treat the club foot in the foal (i.e., extended toe shoes) should never be used in the adult animals because adult animals with club feet frequently have damage to the dorsal laminae similar to that found in horses with laminitis. Toe extensions can markedly increase the detrimental mechanical forces that are considered to exacerbate laminitis."

For mild cases of club foot--grades I and II--rasping the heels at 10-14 day intervals might suffice to achieve a better hoof angle.

"Not a lot all at once," O'Grady cautions. "Instead, take the horse's heels down in moderation at frequent intervals. Rasp from the point of the frog back to the heel in a tapered fashion, leaving everything in front of the point of the frog on the bottom of the foot--this will leave the sole intact. Then remove any excessive hoof wall at the toe from the front of the foot; i.e., back up the toe. This will decrease the toe length by shortening the dorsal hoof wall from the front. This will also minimize leverage on the laminae and shift weight-bearing back towards the heels." This will likely be the maintenance schedule for the rest of the horse's life.

To help determine how much heel to trim, Sigafoos says to first walk out the horse on a very flat, hard surface and look at how the hoof contacts the ground at a walk.

"If the horse sets the hoof down dramatically heel-first (particularly when compared to the opposite hoof), then the heel is probably too high and should be lowered gradually over time," he says. "If necessary, one can leave the horse barefoot for a few weeks (if possible) and gradually lower the heels every other day or so with a few passes of a rasp. In most cases, the stride will even up more, and the foot will achieve a flatter strike pattern.

"If the horse sets his foot down flat, the heel height is probably fairly close to a comfortable height for the horse," he adds. "If the horse lands toe first, one should be careful not to remove any heel at all, particularly if the horse is lame."

The prognosis for mild cases is good; the horse should be able to perform in any disciplines. The affected hoof should be fairly normal by the third trim. Even though trimming can yield adequate correction, O'Grady notes that these horses will still likely have thin or flat soles or decreased sole production due to an increase in weight-bearing on the toe under P3.

"This is where the biggest problem comes in," he says. "They are very prone to bruising, being tender-footed, etc., because they don't have the protection of the sole between the ground and the coffin bone."

O'Grady also says that even with good shoeing, the foot tends to contract over time. "You're always fighting a high heel, therefore you're not utilizing all of the physiological structures in the back of the foot. So over time with this high heel, the foot is going to slowly contract. It's going to become narrow."

For the more severe grade III and IV cases, recommended treatment is check ligament surgery to return the bone and the hoof capsule to normal alignment.

"This surgery gives enough added length to the DDFT so you can realign the bone within the hoof capsule through trimming. In other words, to put the weight of the horse back on the surface of the coffin bone (instead of just the toe)," says O'Grady.

"Immediately before surgery, the heels are lowered appropriately and a steel shoe with a toe extension is applied," he continues. "Surgery can improve conformation of the severely affected foot to a large extent. However, close attention to good trimming and shoeing remains a lifelong commitment; trimming should be done at monthly intervals.

"The farrier still has to maintain the conformation of the foot after surgery," O'Grady adds. "The hoof still grows to some degree the way it did before--the heel is going to grow faster and thicker and you'll need to bring the toe back in the front to keep the alignment around the bone. You don't just cut the ligament and walk away from it; you have to have a farrier who is knowledgeable to maintain the hoof."

For an adult horse, surgical recovery takes about four to six months. However, the procedure is "absolutely, unbelievably successful," O'Grady states. "We do it with the horse standing under local anesthesia, and it's a very, very easy procedure."

For owners who don't want to use surgical correction for severely affected horses, the veterinarian and farrier use a shoeing technique. The heels are lowered as much as possible from the point of the frog back to the heel in a tapered manner, and the toe is backed up from the dorsal hoof wall. If the heels are lowered excessively, this will place excess pressure on the shortened DDFT unit, resulting in discomfort. To counteract this tension, a wedge is inserted between the shoe and the heel. Explains O'Grady, "If we take three degrees off of the heel, we've put the surface on the coffin bone in a little better relationship with the ground. But, because we've lowered the heel, we have increased the tension in the tendon. So we insert a heel wedge in there that is slightly thicker than the amount rasped off. This raises the horse back up and makes him comfortable. The horse grows sole almost immediately and stays sound." (See "Correcting a Club Foot" on page 68.)

Because the foot will grow the same, the horse will always need to be trimmed in this manner and wear the wedge. "We use this type of treatment not only in horses that should have surgical intervention, but also in many grade 3 cases as well," says O'Grady. "It maintains a better alignment of P3 within the hoof capsule while the surgery being a release procedure allows you to change the angulation of the bone and the hoof capsule."

Reducing Hoof Problems

Regular, careful hoof care can go a long way in minimizing the effects of a club foot specifically, and foot and hoof problems in general.

"Probably the most important preventive therapy for hoof problems is good hoof care," says Sigafoos. "For horses that wear shoes, it's important to shoe them frequently so that the toes can be kept short and the hoof at a consistent angle. Quite often horses are shod extremely carefully by a skilled farrier only to have the work undone by the owner allowing the feet to get too long between shoeing periods. Hooves that are excessively long are the underlying cause of the majority of hoof problems that we encounter. If it is necessary to extend the shoeing cycle to prevent nail damage to the hoof wall, alternative methods of shoeing (such as glue-on shoes) should be considered to overcome this problem."

If you have a horse with high heels, be sure to have the club foot evaluated by a veterinarian and a farrier. "If the therapy provided by your farrier and veterinarian results in the resolution of a lameness problem, they might recommend a 'baseline' radiograph for future reference," Sigafoos states. "It is important to remember that every case is different--what helped your neighbor's horse won't necessarily help yours. Your farrier and veterinarian are experienced professionals and can offer excellent suggestions for managing and preventing problems for your horse."

FURTHER READING

For more information on club foot and other foot care topics, see O'Grady's web site at www.equipodiatry.com.

5 TIPS: Mature Club Foot

A club foot is when the hoof angle is raised and the horse walks on his toe due to a shortening of the musculotendinous unit (which includes the tendon that attaches under the foot and the muscles attaching up by the elbow).

A horse can be born with a club foot (congenital) or can acquire it (from poor shoeing or injury) as he grows.

Treatment is by corrective trimming, shoeing, and/or surgery; some mild cases do best with no treatment at all.